The invention relates in general to methods for determining positions of transducers (e.g., antennas) configured for receiving and/or transmitting wave signals, as well as related devices and systems. In particular, it is directed to methods for designing phased-arrays according to a specified, target beamshape. It also relates to beamforming techniques, i.e., methods for beamforming signals or computing beamformed signals, by explicitly targeting designed regions of interest.
Beamforming combines networks of antennas or sensors coherently so as to achieve a beamshape with desirable properties such as high directivity, reduced side-lobes, and improved signal-to-noise ratio (SNR).
Beamforming is often thought of as steering the array to focus on a particular point. This conception, however, has a number of drawbacks. It cannot adjust for small errors in direction of interest estimates, nor cope well with moving devices. Additionally, often a region or regions is what is desired, e.g., to scan the sky in radio astronomy or an organ in ultrasound.
The so-called flexibeam framework [P. Hurley and M. Simeoni, “Beamforming towards regions of interest for multi-site mobile networks,” in International Zurich Seminar on Communications, 2016, p. 94] was developed to determine, in a data independent fashion, beamforming weights so as to target a general spatial region. The framework takes as input fixed antenna locations, and approximates the target beamshapes.